Individual Patient Data Pooled Analysis of Randomized Trials of Bivalirudin versus Heparin in Acute Myocardial Infarction: Rationale and Methodology

Bivalirudin vs Heparin Anticoagulation in STEMI: Confirmation of the BRIGHT-4 Results

BACKGROUND

In the BRIGHT-4 (Bivalirudin With Prolonged Full-Dose Infusion During Primary PCI Versus Heparin Trial-4), anticoagulation with bivalirudin plus a 2- to 4-hour high-dose infusion after percutaneous coronary intervention (PCI) reduced all-cause mortality and bleeding without increasing reinfarction or stent thrombosis compared with heparin alone in patients with ST-segment elevation myocardial infarction (STEMI). These findings require external validation.

OBJECTIVES

This study sought to determine outcomes of bivalirudin vs heparin anticoagulation during PCI in STEMI.

METHODS

We performed an individual-patient-data meta-analysis of all large randomized trials of bivalirudin vs heparin in STEMI patients undergoing primary PCI performed before BRIGHT-4. The primary endpoint was all-cause mortality.

RESULTS

Six trials randomizing 15,254 patients were included. Pooled across all regimens of bivalirudin and glycoprotein IIb/IIIa inhibitor (GPI) use, bivalirudin reduced 30-day all-cause mortality (2.5% vs 2.9%; adjusted OR: 0.78; 95% CI: 0.62-0.99), cardiac mortality (adjusted OR: 0.69; 95% CI: 0.54-0.88), and major bleeding (adjusted OR: 0.53; 95% CI: 0.44-0.64) but increased reinfarction (adjusted OR: 1.30; 95% CI: 1.02-1.65) and stent thrombosis (adjusted OR: 1.43; 95% CI: 1.05-1.93) compared with heparin. In 4 trials in which 6,244 patients were randomized to bivalirudin plus a high-dose post-PCI infusion vs heparin without planned GPI use (the BRIGHT-4 regimens), 30-day all-cause mortality occurred in 1.8% vs 2.9% of patients, respectively (adjusted OR: 0.74; 95% CI: 0.48-1.12), and bivalirudin reduced cardiac mortality (adjusted OR: 0.62; 95% CI: 0.39-0.97) and major bleeding (adjusted OR: 0.49; 95% CI: 0.35-0.70), with similar rates of reinfarction (adjusted OR: 0.89; 95% CI: 0.58-1.38) and stent thrombosis (adjusted OR: 0.80; 95% CI: 0.41-1.57).

CONCLUSIONS

In STEMI patients undergoing primary PCI, bivalirudin with a 2- to 4-hour post-PCI high-dose infusion reduced cardiac mortality and major bleeding without an increase in ischemic events compared with heparin monotherapy with provisional GPI use, confirming the BRIGHT-4 results.

Bivalirudin Versus Heparin During PCI in NSTEMI: Individual Patient Data Meta-Analysis of Large Randomized Trials

BACKGROUND

The benefit:risk profile of bivalirudin versus heparin anticoagulation in patients with non-ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention (PCI) is uncertain. Study-level meta-analyses lack granularity to provide conclusive answers. We sought to compare the outcomes of bivalirudin and heparin in patients with non-ST-segment-elevation myocardial infarction undergoing PCI.

METHODS

We performed an individual patient data meta-analysis of patients with non-ST-segment-elevation myocardial infarction in all 5 trials that randomized ≥1000 patients with any myocardial infarction undergoing PCI to bivalirudin versus heparin (MATRIX [Minimizing Adverse Hemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox], VALIDATE-SWEDEHEART [Bivalirudin Versus Heparin in ST-Segment and Non-ST-Segment Elevation Myocardial Infarction in Patients on Modern Antiplatelet Therapy in the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies Registry Trial], ISAR-REACT 4 [Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 4], ACUITY [Acute Catheterization and Urgent Intervention Triage Strategy], and BRIGHT [Bivalirudin in Acute Myocardial Infarction vs Heparin and GPI Plus Heparin Trial]). The primary effectiveness and safety end points were 30-day all-cause mortality and serious bleeding.

RESULTS

A total of 12 155 patients were randomized: 6040 to bivalirudin (52.3% with a post-PCI bivalirudin infusion), and 6115 to heparin (53.2% with planned glycoprotein IIb/IIIa inhibitor use). Thirty-day mortality was not significantly different between bivalirudin and heparin (1.2% versus 1.1%; adjusted odds ratio, 1.24 [95% CI, 0.86-1.79]; P=0.25). Cardiac mortality, reinfarction, and stent thrombosis rates were also not significantly different. Bivalirudin reduced serious bleeding (both access site-related and non-access site-related) compared with heparin (3.3% versus 5.5%; adjusted odds ratio, 0.59; 95% CI, 0.48-0.72; P<0.0001). Outcomes were consistent regardless of use of a post-PCI bivalirudin infusion or routine lycoprotein IIb/IIIa inhibitor use with heparin and during 1-year follow-up.

CONCLUSIONS

In patients with non-ST-segment-elevation myocardial infarction undergoing PCI, procedural anticoagulation with bivalirudin and heparin did not result in significantly different rates of mortality or ischemic events, including stent thrombosis and reinfarction. Bivalirudin reduced serious bleeding compared with heparin arising both from the access site and nonaccess sites.

Inferior ST segment elevation myocardial infarction combined with hyperextension cervical spine injury: A rare case report

RATIONALE

Inferior ST-segment elevation myocardial infarction (STEMI) is usually caused by acute occlusion of the right coronary artery or left circumflex coronary artery (LCX). Inferior STEMI can cause a high-grade atrioventricular block, sinus bradycardia, and hypotension, leading to hemodynamic collapse, syncope, and disturbance of consciousness.

PATIENT CONCERNS

A case of a sudden disturbance of consciousness after chest tightness as the initial symptom, followed by incomplete paralysis and paresthesia of the extremities due to the collision of the face with the ground.

DIAGNOSES

Coronary angiography showed about 99% of stenosis in the LCX. Cervical spine magnetic resonance imaging showed C2/3, C3/4, C4/5, and C5/6 intervertebral disc herniation with secondary spinal stenosis, spinal cord compression, and edema. The patient was diagnosed with inferior STEMI combined with hyperextension cervical spine injury.

INTERVENTIONS AND OUTCOMES

Bivalirudin was used for anticoagulation, the LCX lesion was pre-expanded with a balloon and the thrombus was removed, and anti-platelet aggregation therapy was given postoperatively. After rehabilitation therapy, hyperextension cervical spine injury improved. There was no recurrence of syncope and precordial pain during the 6-month follow-up.

LESSONS

Hyperextension cervical spine injury has unique hemodynamic features that mimic those associated with inferior STEMI, so a detailed medical history inquiry and physical examination should be carried out to avoid missed diagnoses.

Antithrombotic Treatment in Coronary Artery Disease

Coronary artery disease exhibits growing mortality and morbidity worldwide despite the advances in pharmacotherapy and coronary intervention. Coronary artery disease is classified in the acute coronary syndromes and chronic coronary syndromes according to the most recent guidelines of the European Society of Cardiology. Antithrombotic treatment is the cornerstone of therapy in coronary artery disease due to the involvement of atherothrombosis in the pathophysiology of the disease. Administration of antiplatelet agents, anticoagulants and fibrinolytics reduce ischemic risk, which is amplified early post-acute coronary syndromes or post percutaneous coronary intervention; though, antithrombotic treatment increases the risk for bleeding. The balance between ischemic and bleeding risk is difficult to achieve and is affected by patient characteristics, procedural parameters, concomitant medications and pharmacologic characteristics of the antithrombotic agents. Several pharmacological strategies have been evaluated in patients with coronary artery disease, such as the effectiveness and safety of antithrombotic agents, optimal dual antiplatelet treatment schemes and duration, aspirin de-escalation strategies of dual antiplatelet regimens, dual inhibition pathway strategies as well as triple antithrombotic therapy. Future studies are needed in order to investigate the gaps in our knowledge, including special populations.

Periprocedural Antithrombotic Treatment in Complex Percutaneous Coronary Intervention

ABSTRACT

In recent years, the management of complex lesions in patients undergoing percutaneous coronary intervention (PCI) constitutes a field of high interest and concern for the interventional cardiology. As more and more studies demonstrate the increased hazard of ischemic events in this group of patients, it is of paramount importance for the physicians to choose the optimal periprocedural (pre-PCI, during-PCI and post-PCI) antithrombotic treatment strategies wisely. Evidence regarding the safety and efficacy of current anticoagulation recommendation, the possible beneficial role of the pretreatment with a potent P2Y12 inhibitor in the subgroup of patients with non-ST segment elevation myocardial infarction with complex lesions, and the impact of a more potent P2Y12 inhibitor in individuals with stable coronary artery disease undergoing complex PCI are needed. This will provide and serve as a guide to clinicians to deploy the maximum efficacy of the current choices of antithrombotic therapy, which will lead to an optimal balance between safety and efficacy in this demanding clinical scenario.

Bleeding avoidance strategies in percutaneous coronary intervention

For many years, bleeding has been perceived as an unavoidable consequence of strategies aimed at reducing thrombotic complications in patients undergoing percutaneous coronary intervention (PCI). However, the paradigm has now shifted towards bleeding being recognized as a prognostically unfavourable event to the same extent as having a new or recurrent ischaemic or thrombotic complication. As such, in parallel with progress in device and drug development for PCI, there is clinical interest in developing strategies that maximize not only the efficacy but also the safety (for example, by minimizing bleeding) of any antithrombotic treatment or procedural aspect before, during or after PCI. In this Review, we discuss contemporary data and aspects of bleeding avoidance strategies in PCI, including risk stratification, timing of revascularization, pretreatment with antiplatelet agents, selection of vascular access, choice of coronary stents and antithrombotic treatment regimens.

Heparin-induced thrombocytopenia and cardiovascular surgery

Clinicians generally counsel patients with a history of heparin-induced thrombocytopenia (HIT) to avoid heparin products lifelong. Although there are now many alternative (nonheparin) anticoagulants available, heparin avoidance remains challenging for cardiac surgery. Heparin is often preferred in the cardiac surgery setting based on the vast experience with the agent, ease of monitoring, and reversibility. To "clear" a patient with a history of HIT for cardiac surgery, hematologists must first confirm the diagnosis of HIT, which can be challenging due to the ubiquity of heparin exposure and frequency of thrombocytopenia in patients in the cardiac intensive care unit. Next, the "phase of HIT" (acute HIT, subacute HIT A/B, or remote HIT) should be established based on platelet count, immunoassay for antibodies to platelet factor 4/heparin complexes, and a functional assay (eg, serotonin release assay). As long as the HIT functional assay remains positive (acute HIT or subacute HIT A), cardiac surgery should be delayed if possible. If surgery cannot be delayed, an alternative anticoagulant (preferably bivalirudin) may be used. Alternatively, heparin may be used with either preoperative/intraoperative plasma exchange or together with a potent antiplatelet agent. The optimal strategy among these options is not known, and the choice depends on institutional experience and availability of alternative anticoagulants. In the later phases of HIT (subacute HIT B or remote HIT), brief intraoperative exposure to heparin followed by an alternative anticoagulant as needed in the postoperative setting is recommended.

Reperfusion After Fibrinolytic Therapy (RAFT): An open-label, multi-centre, randomised controlled trial of bivalirudin versus heparin in rescue percutaneous coronary intervention

BACKGROUND

The safety and efficacy profile of bivalirudin has not been examined in a randomised controlled trial of patients undergoing rescue PCI.

OBJECTIVES

We conducted an open-label, multi-centre, randomised controlled trial to compare bivalirudin with heparin ± glycoprotein IIb/IIIa inhibitors (GPIs) in patients undergoing rescue PCI.

METHODS

Between 2010-2015, we randomly assigned 83 patients undergoing rescue PCI to bivalirudin (n = 42) or heparin ± GPIs (n = 41). The primary safety endpoint was any ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) bleeding at 90 days. The primary efficacy endpoint was infarct size measured by peak troponin levels as a multiple of the local upper reference limit (Tn/URL). Secondary endpoints included periprocedural change in haemoglobin adjusted for red cells transfused, TIMI (Thrombolysis in Myocardial Infarction) bleeding, ST-segment recovery and infarct size determined by the Selvester QRS score.

RESULTS

The trial was terminated due to slow recruitment and futility after an interim analysis of 83 patients. The primary safety endpoint occurred in 6 (14%) patients in the bivalirudin group (4.8% GPIs) and 3 (7.3%) in the heparin ± GPIs group (54% GPIs) (risk ratio, 1.95, 95% confidence interval [CI], 0.52-7.3, P = 0.48). Infarct size was similar between the two groups (mean Tn/URL, 730 [±675] for bivalirudin, versus 984 [±1585] for heparin ± GPIs, difference, 254, 95% CI, -283-794, P = 0.86). There was a smaller decrease in the periprocedural haemoglobin level with bivalirudin than heparin ± GPIs (-7.5% [±15] versus -14% [±17], difference, -6.5%, 95% CI, -0.83-14, P = 0.0067). The rate of complete (≥70%) ST-segment recovery post-PCI was higher in patients randomised to heparin ± GPIs compared with bivalirudin.

CONCLUSIONS

Whether bivalirudin compared with heparin ± GPI reduces bleeding in rescue PCI could not be determined. Slow recruitment and futility in the context of lower-than-expected bleeding event rates led to the termination of this trial (ANZCTR.org.au, ACTRN12610000152022).

Antithrombotic treatment in primary percutaneous coronary intervention

INTRODUCTION

Despite a timely mechanical reperfusion with primary percutaneous coronary intervention (pPCI) patients presenting with ST-elevation myocardial infarction (STEMI) display an increased risk of adverse cardiovascular events. Several studies have demonstrated that guideline-directed antithrombotic therapy is effective to reduce this risk. However, there is still much to be accomplished to improve antithrombotic therapies in this clinical setting.

AREAS COVERED

This paper reviews current data on antithrombotic therapy in STEMI patients undergoing pPCI.

EXPERT OPINION

Antithrombotic therapy for STEMI patients undergoing pPCI should take into account the variability of thrombotic and bleeding risk in the short and long term. Patients with STEMI profit from the administration of early onset antiplatelet agents and anticoagulation to achieve sufficient and predictable antithrombotic effect at the time of pPCI. Thereafter, antithrombotic therapies should be tailored to individual risk of recurrence over the long term, to avoid excess bleeding, while ensuring adequate secondary ischemic prevention.

Antithrombotic Therapy in Acute Coronary Syndromes: Current Evidence and Ongoing Issues Regarding Early and Late Management

A few decades ago, the understanding of the pathophysiological processes involved in the coronary artery thrombus formation has placed anticoagulant and antiplatelet agents at the core of the management of acute coronary syndrome (ACS). Increasingly potent antithrombotic agents have since been evaluated, in various association, timing, or dosage, in numerous randomized controlled trials to interrupt the initial thrombus formation, prevent ischemic complications, and ultimately improve survival. Primary percutaneous coronary intervention, initial parenteral anticoagulation, and dual antiplatelet therapy with potent P2Y₁₂ inhibitors have become the hallmark of ACS management revolutionizing its prognosis. Despite these many improvements, much more remains to be done to optimize the onset of action of the various antithrombotic therapies, for further treating and preventing thrombotic events without exposing the patients to an unbearable hemorrhagic risk. The availability of various potent P2Y₁₂ inhibitors has opened the door for individualized therapeutic strategies based on the clinical setting as well as the ischemic and bleeding risk of the patients, while the added value of aspirin has been recently challenged. The strategy of dual-pathway inhibition with P2Y₁₂ inhibitors and low-dose non-vitamin K antagonist oral anticoagulant has brought promising results for the early and late management of patients presenting with ACS with and without indication for oral anticoagulation. In this updated review, we aimed at describing the evidence supporting the current gold standard of antithrombotic management of ACS. More importantly, we provide an overview of some of the ongoing issues and promising therapeutic strategies of this ever-evolving topic.

Antiplatelet strategies in acute coronary syndromes: design and methodology of an international collaborative network meta-analysis of randomized controlled trials

INTRODUCTION

The optimal choice of oral P2Y<inf>12</inf> receptor inhibitors has the potential to significantly influence outcomes. We seek to compare the safety and efficacy of the three most commonly used oral P2Y<inf>12</inf> receptor inhibitors (clopidogrel, prasugrel, and ticagrelor) in acute coronary syndromes (ACS) via a comprehensive systematic review and network meta-analysis.

EVIDENCE ACQUISITION

In line with the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines, we performed a comprehensive search for RCTs which compared cardiovascular and hemorrhagic outcomes after use of at least two of the distinct oral P2Y<inf>12</inf> receptor inhibitors (i.e. clopidogrel, prasugrel, and ticagrelor). A search strategy has been designed to systematically search multiple databases, including MEDLINE with PubMed interface, The Cochrane Central Register of Controlled Trials, and Embase. In addition, key inclusion criteria will be trial size of at least 100 patients and at least 1 month of follow-up time. Several prespecified subgroups will be explored, including Asian patients, patients presenting with ST-elevation myocardial infarction, patients of advanced age, and others.

EVIDENCE SYNTHESIS

Exploratory frequentist pairwise meta-analyses will be based primarily on a random-effects method, relying on relative risks (RR) for short-term outcomes and incidence rate ratios (IRR) for long-term outcomes. Inferential frequentist network meta-analysis will be based primarily on a random-effects method, relying on RR and IRR as specified above. Results will be reported as point summary of effect, 95% CI, and P values for effect, and graphically represented using forest plots.

CONCLUSIONS

An international collaborative network meta-analysis has begun to comprehensively analyze the safety and efficacy of prasugrel, ticagrelor and clopidogrel, each on a background of aspirin, for management of patients with ACS. It is our hope that the rigor and breadth of the undertaking described herein will provide novel insights that will inform optimal patient care for patients with ACS treated conservatively, or undergoing revascularization.

Pharmacological Agents Targeting Thromboinflammation in COVID-19: Review and Implications for Future Research

Coronavirus disease 2019 (COVID-19), currently a worldwide pandemic, is a viral illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The suspected contribution of thrombotic events to morbidity and mortality in COVID-19 patients has prompted a search for novel potential options for preventing COVID-19-associated thrombotic disease. In this article by the Global COVID-19 Thrombosis Collaborative Group, we describe novel dosing approaches for commonly used antithrombotic agents (especially heparin-based regimens) and the potential use of less widely used antithrombotic drugs in the absence of confirmed thrombosis. Although these therapies may have direct antithrombotic effects, other mechanisms of action, including anti-inflammatory or antiviral effects, have been postulated. Based on survey results from this group of authors, we suggest research priorities for specific agents and subgroups of patients with COVID-19. Further, we review other agents, including immunomodulators, that may have antithrombotic properties. It is our hope that the present document will encourage and stimulate future prospective studies and randomized trials to study the safety, efficacy, and optimal use of these agents for prevention or management of thrombosis in COVID-19.